In safety-relevant systems, in which, for example, standard Ethernet components, processing units (multicore, many-core, μC, μP) and standard operating systems (for example, QNX or Linux) are used, it is often impossible to protect the entire system using self-tests. In many safety-relevant applications, for example, in functions for highly automated driving, calculations are carried out redundantly, for example, in so-called lockstep methods. Such lockstep calculations may also be implemented, for example, as pure software locksteps without hardware support. In systems where demands for safety, availability, and performance of the systems are particularly high, the safety functions may be calculated in a distributed manner, i.e., on different separate hardware units.
German Patent Application No. DE 103322700 A1 describes a processor unit including two execution units, which run the same program, and comparison means, which check whether the states of the execution units arising while they run the same programs are identical.